<!DOCTYPE html>
<html lang="en"xmlns="http://www.w3.org/1999/xhtml"  xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--th:value  属性复制，设置当前元素的value值，常用，优先级仅比th:text高-->
<input type="text" th:value="${username}">
</body>
</html>